The Environmental Protection Agency has begun for the first time to regulate a class of synthetic chemicals known as “forever chemicals” in America’s drinking water.Kim Tingley, a contributing writer for The New York Times Magazine, explains how these chemicals, which have been linked to liver disease and other serious health problems, came to be in the water supply — and in many more places.Guest: Kim Tingley, a contributing writer for The New York Times Magazine.Background reading: “Forever chemicals” are everywhere. What are they doing to us?The E.P.A. issued its rule about “forever chemicals” last week.For more information on today’s episode, visit nytimes.com/thedaily. Transcripts of each episode will be made available by the next workday.